Hi There,
I agree with donthomas, NetFlow will only focus on IP addresses, ports and traffic volumes. If you want to understand more about applications and users you need to look at network packets (deep packet inspection). To give you an idea what can be done we have integrated our LANGuardian product with Orion so that you can really see what users are doing on your network. You can access a demo of the integration at this link:
http://demo2.netfort.com/Orion/SummaryView.aspx?viewid=1
The video below also shows this integration in acttion.
Darragh